电位滴定结合偏最小二乘算法用于溶液中肉桂酸和L-苯丙氨酸的同时测定

A Chemometrics-Assisted Potentiometric Method for Simultaneous Determination of Cinnamic Acid and L-Phenylalanine

结合自动电位滴定和化学计量学算法,建立同时测定溶液中肉桂酸、L-苯丙氨酸和硫酸铵的方法。通过正交设计25组校正集溶液,通过留一验证法对校正集最佳主成分进行选择,得到偏最小二乘法较佳模型,并对模拟样品进行分析。结果显示:肉桂酸、L-苯丙氨酸、硫酸铵的回收率分别在92.9%～104.4%、94.9%～101.5%、96.6%～105.1%之间。基于PLS的方法可以方便解析重叠的滴定图谱,不需要预先分离即可预测成分浓度。

In this work, we proposed a new method for the simultaneous determination of cinnamic acid, L-phenylalanine and amonium sulfate in solution using combined potentiometric titration and chemometrics. The partial least squares （PLS） algo- rithm was applied and 25 standard mixtures of the compounds were prepared according to orthogonal experimental design for calibration set. The commonly used leave-one-out cross-validiation method was used to select the optimum number of factors in the PLS model. An independent set of synthetic raw mixtures was employed to evaluate the prediction performance of the resulting models. The results showed that the recovery values ranged from 92.9% to 104.4% for cinnamic acid, 94.9% to 101.5% for L-phenylalanine, and 96.6% to 105.1% for amonium sulfate respectively. The study proves the feasibility of simultaneous spectrometric determination of cinnamic acid, L-phenylalanine and ammonium salts in raw mixtures without preliminary separation steps.